1. Field of the Invention
The present invention relates to a solid catalyst component for xcex1-olefin polymerization. More specifically, the present invention relates to a solid catalyst component for xcex1-olefin polymerization having a narrow particle size distribution and high catalytic activity, a catalyst for xcex1-olefin polymerization comprising said solid catalyst component and a process for producing poly-xcex1-olefins with said catalyst.
2. Description of the Related Arts
As is well known, the Ziegler-Natta catalyst comprising a transition metal compound (IV to VI Groups) and an organometallic compound (I, II and XIII Groups) is used for producing isotactic polymers of an xcex1-olefin such as propylene, 1-butene or the like.
For the improved operability, it is desirable to produce poly-xcex1-olefins having a substantially uniform particle diameter and being free from fine powder. Catalyst residues deriving from the transition metal compound and the organometallic compound remain in the resulting poly-xcex1-olefins. An equipment for removal of the catalyst residue is required for removal and deactivation of the catalyst residue, which arises various adverse effects on the stability and processability of poly-xcex1-olefins, and the like.
The problem of the catalyst residue is solved by increasing the catalytic activity, which is defined as the weight of the produced poly-xcex1-olefin per unit weight of the catalyst. This method does not require any special equipment for removal of the catalyst residue, and reduces the production cost of poly-xcex1-olefins. The catalyst having extremely high catalytic activity is required to enable a deashing-free process that is industrially advantageous.
The higher catalytic activity, however, decreases the bulk density of the resulting polymer particles. Therefore, a catalyst having a high activity and giving polymers of high bulk density and favorable particle properties, is required. Development of the solid catalyst component having the favorable particle properties and high polymerization activity has been attempted because the particle properties of the resulting polymers significantly depend upon the particle properties of the solid catalyst component.
With respect to an improvement the particle properties and narrowing the distribution of particle size, in polymerization of ethylene, there are proposed uses of a solid catalyst component preparing by supporting a titanium-magnesium compound on a silica gel carrier to overcome the problems (JP-A-54-148098 and JP-A-56-47407). It is also disclosed in JP-A-62-256802 that, in polymerization of propylene, particle properties of the resulting polypropylene are markedly improved by using the solid catalyst component obtained by soaking a titanium-magnesium compound in silica gel as a carrier.
Although improving the particle properties to some extent, these proposed catalysts have relatively low activity and cause a large amount of silica gel used as the carrier to contaminate in the final products. The contaminated silica gel deteriorates the quality of final products and causes fish eye in film products.
A variety of solid catalyst components having a high catalytic activity have also been proposed.
By way of example, it is known that a Tixe2x80x94Mg complex-type solid catalyst, which is obtained by reducing a tetravalent titanium compound with an organomagnesium compound in the presence of an organosilicon compound to obtain an eutectic crystal of magnesium and titanium, is used in combination with an organoaluminum compound as a co-catalyst and an organosilicon compound as a third component to realize xcex1-olefin polymerization of relatively high stereoregularity and high activity (JP-B-03-43283 and JP-A-01-319508). Another proposed technique shows that coexistence of an ester in the reduction of a tetravalent titanium compound with an organomagnesium compound in the presence of an organosilicon compound further improves polymerization of higher stereoregularity and higher activity (JP-A-07-206017).
Although these proposed techniques realize an extraction-free and deashing-free process, further improvement in particle properties of the resulting polymers is desired.
An object of the present invention is to provide a solid catalyst component for xcex1-olefin polymerization, which has a high catalytic activity and a narrow distribution of particle size, contains less fine powder and is capable of giving a poly-xcex1-olefin having a high bulk density and favorable particle properties efficiently.
Another object of the present invention is to provide a solid catalyst component for xcex1-olefin polymerization and a solid for xcex1-olefin polymerization, which give a poly-xcex1-olefin having a high stereoregularity in addition to the above advantages, as well as a process for producing a poly-xcex1-olefin of favorable particle properties with said catalyst.
According to the present invention, there is provided a solid catalyst component for xcex1-olefin polymerization having a particle size distribution of not less than 6.0 in terms of the value of N in a Rosin-Rammler function of particle size distribution and giving a catalytic activity of not less than 10,000 ((g-polymer produced/g-solid catalyst component)/hour) in polymerization.
The present invention further provides (A) a solid catalyst component for xcex1-olefin polymerization containing a trivalent titanium compound, obtained by a process which comprises reducing a titanium compound represented by the general formula of Ti(OR1)aX4xe2x88x92a (wherein R1 represents a hydrocarbon group having 1 to 20 carbon atoms; X represents a halogen atom; xe2x80x9caxe2x80x9d is a number satisfying 0xe2x89xa6axe2x89xa64) with an organomagnesium compound in the presence of an organosilicon compound having an Sixe2x80x94O bond and an ester to obtain a solid product, successively adding a mixture of an ether and titanium tetrachloride and an organic acid halide in this sequence to the solid product for treatment, and further treating the treated solid product with a mixture of an ether and titanium tetrachloride or a mixture of an ether, titanium tetrachloride and an ester.
The present invention also provides a catalyst for xcex1-olefin polymerization comprising:
(A) the solid catalyst component for xcex1-olefin polymerization described above;
(B) an organoaluminum compound; and
(C) an electron-donor compound.
The present invention further provides a process for producing a poly-xcex1-olefin with said catalyst.
The present invention gives a poly-xcex1-olefin having favorable particle properties. Preferably the present invention enables high stereoregular polymerization of an xcex1-olefin.
The poly-xcex1-olefin here means a homopolymer of an xcex1-olefin or a copolymer of an xcex1-olefin and another xcex1-olefin or ethylene.
The present invention will be explained in detail below.
There is described a solid catalyst component for xcex1-olefin polymerization of the present invention, which has a particle size distribution of not less than 6.0 in terms of the value of N in a Rosin-Rammler function of particle size distribution and gives a catalytic activity of not less than 10,000 ((g-polymer produced/g-solid catalyst component)/hour) in polymerization.
The factor N in the Rosin-Rammler function of particle size distribution given below is generally known as an index representing the degree of the distribution of solid particle diameter (see Rosin, P. and E. Rammler: J. Inst. Fuel, 7, p29(1933) and Handbook of Chemical Engineering, 3rd. ed. pp. 361-362):
R(Dp)=100 exp{xe2x88x92(Dp/De)N}
wherein R(Dp) represents a residual cumulative percentage; Dp represents a particle diameter; and De represents a particle diameter corresponding to [at] R(Dp)=36.8%. The larger N tends to narrow the particle size distribution. The solid catalyst component of the large N has a narrow particle size distribution and gives a polymer having a high bulk density and favorable particle properties and containing less fine powder, thereby being favorable in industrial. The value of N of solid catalyst component of the present invention is preferably not less than 6.2 or more, more preferably not less than 6.4.
The solid catalyst component has the catalytic activity of not less than 10,000, preferably not less than 15,000, more preferably not less than 20,000, and most preferably not less than 30,000 ((g-polymer produced/g-solid catalyst component)/hour).
The desirable catalyst of the present invention gives a poly-xcex1-olefin of high stereoregularity.
Conditions of polymerization for determining the above catalytic activity are those adopted in Example 1 described below. In other words, the catalytic activity and bulk density can be determined by polymerizing propylene under the same conditions as in Example 1 except changing a solid catalyst component.
The solid catalyst component for xcex1-olefin polymerization described above is preferably one produced by the following method.
The solid catalyst component of the present invention is a solid catalyst component for xcex1-olefin polymerization containing a trivalent titanium compound, which is obtained by reducing a titanium compound represented by the general formula of Ti(OR1)aX4xe2x88x92a (wherein R1 represents a hydrocarbon group of 1 to 20 carbon atoms; X represents a halogen atom; 0xe2x89xa6axe2x89xa64) with an organomagnesium compound in the presence of an organosilicon compound having an Sixe2x80x94O bond and an ester to obtain a solid product, successively adding a mixture of an ether and titanium tetrachloride and an organic acid halide in this sequence to the solid product for treatment, and further treating the treated solid product with a mixture of an ether and titanium tetrachloride or a mixture of an ether, titanium tetrachloride and an ester.
The following describes the trivalent titanium compound-containing solid catalyst component for xcex1-olefin polymerization in detail.
(a) Titanium Compound
In the titanium compound represented by the general formula of Ti(OR1)aX4xe2x88x92a (wherein R1 represents a hydrocarbon group having 1 to 20 carbon atoms; X represents a halogen atom; 0xe2x89xa6axe2x89xa64), specific examples of R1 include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, amyl, isoamyl, tert-amyl, hexyl, heptyl, octyl, decyl, dodecyl and the like, aryl groups having up to 20 carbon atoms such as phenyl, cresyl, xylyl, naphthyl and the like, allyl groups such as propenyl and the like, and aralkyl groups having up to 20 carbon atoms such as benzyl and the like. Among these, alkyl groups having 2 to 18 carbon atoms and aryl groups of 6 to 18 carbon atoms are preferable. Linear alkyl groups having 2 to 18 carbon atoms are particularly preferred. Titanium compounds having two or more different OR1 groups can be also used.
Examples of the halogen atom expressed by X include chlorine atom, bromine atom, and iodine atom. Especially preferable is chlorine atom.
The value of xe2x80x9caxe2x80x9d in the titanium compound expressed by the general formula of Ti(OR1)aX4xe2x88x92a satisfies 0xe2x89xa6axe2x89xa64, preferably 2xe2x89xa6axe2x89xa64. Especially preferable is a=4.
Any known method is applicable for synthesis of the titanium compound expressed by the general formula of Ti(OR1)aX4xe2x88x92a. Available methods include one for making Ti(OR1)4 and TiX4 react with each other at a predetermined ratio and one for making TiX4 react with a predetermined amount of the corresponding alcohol(R1OH).
The titanium compound may be diluted with a hydrocarbon or a halogenated hydrocarbon.
The titanium compound expressed by the general formula of Ti(OR1)aX4xe2x88x92a include titanium tetrahalides such as titanium tetrachloride, titanium tetrabromide, titanium tetraiodide and the like, alkoxytitanium trihalides such as methoxytitanium trichloride, ethoxytitanium trichloride, butoxytitanium trichloride, phenoxytitanium trichloride, ethoxytitanium tribromide and the like, dialkoxytitanium dihalides such as dimethoxytitanium dichloride, diethoxytitanium dichloride, dibutoxytitanium dichloride, diphenoxytitanium dichloride, diethoxytitanium dibromide and the like, trialkoxytitanium monohalides such as trimethoxytitanium chloride, triethoxytitanium chloride, tributoxytitanium chloride, triphenoxytitanium chloride, triethoxytitanium bromide and the like, and tetraalkoxytitaniums such as tetramethoxytitanium, tetraethoxytitanium, tetrabutoxytitanium, tetraphenoxytitanium and the like.
(b) Organosilicon Compound having Sixe2x80x94O Bond
The organosilicon compound having an Sixe2x80x94O bond is, for example, expressed by one of the following general formulae:
Si(OR2)mR34xe2x88x92m;
R4(R52SiO)pSiR63;
or
(R72SiO)q
wherein R2 represents a hydrocarbon group of 1 to 20 carbon atoms; R3, R4, R5, R6 and R7 respectively represent a hydrocarbon group having 1 to 20 carbon atoms or hydrogen atom; 0 less than mxe2x89xa64; p is an integer of 1 to 1000; and a is an integer of 2 to 1000.
Specified examples of the organosilicon compound include tetramethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, triethoxyethylsilane, diethoxydiethylsilane, ethoxytriethylsilane, tetraisopropoxysilane, diisopropoxydiisopropylsilane, tetrapropoxysilane, dipropoxydipropylsilane, tetrabutoxysilane, dibutoxydibutylsilane, dicyclopentoxydiethylsilane, diethoxydiphenylsilane, cyclohexyloxytrimethylsilane, phenoxytrimethylsilane, tratraphenoxysilane, triethoxyphenylsilane, hexamethyldisiloxane, hexaethyldisiloxane, hexapropyldisiloxane, octaethyltrisiloxane, dimethylpolysiloxane, diephylpolysiloxane, methylhydropolysiloxane, phenylhydropolysiloxane and the like.
Among these organosilicon compounds, alkoxysilanes expressed by the general formula of Si(OR2)mR34xe2x88x92m are preferable, wherein 1xe2x89xa6mxe2x89xa64. Especially preferable are tertraalkoxysilanes, wherein m is 4.
(c) Ester
As an ester used in the present invention, there can be used organic acid esters, preferably mono-valent and poly-valent carboxylic acid esters including aliphatic carboxylic acid esters, alicyclic carboxylic acid esters, and aromatic carboxylic acid esters. Concrete examples include methyl acetate, ethyl acetate, phenyl acetate, methyl propionate, ethyl propionate, ethyl butyrate, ethyl valerate, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl benzoate, butyl benzoate, methyl toluate, ethyl toluate, ethyl anisate, diethyl succinate, dibutyl succinate, diethyl malonate, dibutyl malonate, dimethyl maleate, dibutyl maleate, diethyl itaconate, dibutyl itaconate, monoethyl phthalate, dimethyl phthalate, methylethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, diphenyl phthalate and the like.
Among these esters, unsaturated aliphatic carboxylic acid esters such as methacrylates and maleates and phthalates are preferable. Especially preferable are phthalic diesters.
(d) Organomagnesium Compound
Any organomagnesium compound having a magnesium-carbon bond can be used as the organomagnesium compound. Preferably used are Grignard compounds represented by the general formula of R8MgX (wherein R8 represents a hydrocarbon group having 1 to 20 carbon atoms; and X represents a halogen atom) as well as dialkylmagnesium compounds and diarylmagnesium compounds represented by the general formula of R9R10Mg (wherein R9 or R10 represents a hydrocarbon group having 1 to 20 carbon atoms). R8, R9 and R10 individually represent alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, amyl, isoamyl, hexyl, octyl, 2-ethylhexyl and the like, aryl groups having up to 20 carbon atoms such as phenyl and the like, aralkyl groups having up to 20 carbon atoms such as benzyl and alkenyl groups having up to 20 carbon atoms as vinyl and propenyl, and may be the same or different.
Concrete examples of the Grignard compound include methylmagnesium chloride, ethylmagnesium chloride, ethylmagnesium bromide, ethylmagnesium iodide, propylmagnesium chloride, propylmagnesium bromide, butylmagnesium chloride, butylmagnesium bromide, sec-butylmagnesium chloride, sec-butylmagnesium bromide, tert-butylmagnesium chloride, tert-butylmagnesium bromide, amylmagnesium chloride, isoamylmagnesium chloride, hexylmagnesium chloride, phenylmagnesium chloride, and phenylmagnesium bromide. Examples of the compound expressed by the general formula of R9R10Mg include dimethylmagnesium, diethylmagnesium dipropylmagnesium, diisopropylmagnesium, dibutylmagnesium, di-sec-butylmagnesium, di-tert-butylmagnesium, butyl-sec-butylmagnesium, diamylmagnesium, dihexylmagnesium, diphenylmagnesium, butylethylmagnesium and the like.
Solvents generally used for the synthesis of the above organomagnesium compounds are ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, diamyl ether, diisoamyl ether, dihexyl ether, dioctyl ether, diphenyl ether, dibenzyl ether, phenetole, anisole, tetrahydrofuran, tetrahydropyran. Hydrocarbon solvents such as hexane, heptane, octane, cyclohexane, methylcyclohexane, benzene, toluene and xylene, and mixed solvents of ether solvents and hydrocarbon solvents are also available.
The organomagnesium compound is preferably used in the form of an ether solution. Favorable examples of the ether used here include ethers having six or more carbon atoms in the molecule and ethers having the cyclic structure. Ether solutions of the Grignard compounds represented by the general formula of R8MgX are especially preferable from the viewpoint of the catalytic performance.
A hydrocarbon-soluble complex of the above organomagnesium compound with an organometallic compound is also available. Examples of the organometallic compound include organic compounds of Li, Be, B, Al and Zn.
(e) Ether
An ether used in the invention preferably includes di-C1-10 alkyl ethers. Examples of the dialkyl ether include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, diamyl ether, diisoamyl ether, dineopentyl ether, dihexyl ether, dioctyl ether, methylbutyl ether, methylisoamyl ether, and ethylisobutyl ether. Among these examples, especially preferable are dibutyl ether and diisoamyl ether.
(f) Organic Acid Halide
Mono-valent and poly-valent carboxylic acid halides including aliphatic carboxyl halides, alicyclic carboxyl halides, and aromatic carboxyl halides can be used as the organic acid halide. Concrete examples include acetyl chloride, propionyl chloride, butyroyl chloride, valeroyl chloride, acryloyl chloride, methacryloyl chloride, benzoyl chloride, toluyl chloride, anisyl chloride, succinyl chloride, malonyl chloride, maleyl chloride, itaconoyl chloride, and phthaloyl chloride.
Among these organic acid halides, aromatic carboxylic acid halides such as benzoyl chloride, toluyl chloride, phthaloyl chloride and the like are preferred. Especially preferable is phthaloyl chloride.
(g) Synthesis of Solid Catalyst Component
The trivalent titanium compound-containing solid catalyst component is obtained by reducing the titanium compound with the organomagnesium compound in the presence of the organosilicon compound and the ester to obtain a solid product, successively adding a mixture of the ether and titanium tetrachloride and the organic acid halide in this sequence to the solid product for treatment, and further treating the treated solid product with a mixture of the ether and titanium tetrachloride or a mixture of the ether, titanium tetrachloride, and the ester. All of these reactions are carried out under an atmosphere of an inert gas such as nitrogen or argon.
Reduction of the titanium compound with the organomagnesium compound may be implemented by adding the organomagnesium compound to a mixture of the titanium compound, the organosilicon compound and the ester, or on the contrary, by adding a mixture of the titanium compound, the organosilicon compound and the ester to a solution of the organomagnesium compound. The method of adding the organomagnesium compound to a mixture of the titanium compound, the organosilicon compound and the ester is preferable from the viewpoint of the catalytic activity.
It is preferable that the titanium compound, the organosilicon compound and the ester are dissolved in or diluted with an appropriate solvent. Preferable examples of the solvent include: aliphatic hydrocarbons such as hexane, heptane, octane, decane and the like; aromatic hydrocarbons such as toluene, xylene and the like; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, decalin and the like; and ethers such as diethyl ether, dibutyl ether, diisoamyl ether, tetrahydrofuran and the like.
The temperature of the reduction is generally in the range of xe2x88x9250 to 70xc2x0 C., preferably in the range of xe2x88x9230 to 50xc2x0 C., and more preferably in the range of xe2x88x9225 to 35xc2x0 C. for the desired activity of the resulting solid catalyst.
A porous substance such as an inorganic oxide or an organic polymer, may coexist in the reduction, so that the solid product is impregnated with the porous substance. The preferable porous substance has a pore volume in the pore radius range of 20 to 200 nm of not less than 0.3 ml/g and a mean particle diameter of 5 to 300 xcexcm.
Examples of the porous inorganic oxide include SiO2, Al2O3, MgO, TiO2, ZrO2, SiO2(Al2O3 complex oxide, MgO(Al2O3 complex oxide, and MgO(SiO2(Al2O3 complex oxide. Examples of the porous polymer include polystyrenes such as polystyrene, styrene-divinylbenzene copolymer, styrene-n,nxe2x80x2-alkylene dimethacrylamide copolymer, styrene-ethylene glycol methyl dimethacrylate copolymer and ethylvinylbenzene-divinylbenzene copolymer, poly(meth)acrylates such as poly(ethyl acrylate), methyl acrylate-divinylbenzene copolymer, ethyl acrylate-divinylbenzene copolymer, poly(methyl methacrylate), methyl methacrylate-divinylbenzene copolymer and poly(ethylene glycol methyl dimethacrylate), polyacrylonitriles such as polyacrylonitrile and acrylonitrile-divinylbenzene copolymer, poly(vinyl chlorides) such as poly(vinyl chloride), polyolefins such as polyethylene, ethylene-methyl acrylate copolymer and polypropylene, poly(vinyl pyrrolidine), poly(vinyl pyridine) and the like. Among these porous substances, SiO2, Al2O3 and styrene-divinylbenzene copolymer are generally used.
The time of dropwise addition is not specifically restricted, but is usually about 30 minutes to about 12 hours. After completion of the reduction, post-reaction may be carried out at the temperature of 20 to 120xc2x0 C.
The amount of the organosilicon compound used is generally in the range of 1 to 50, preferably in the range of 3 to 30, and more preferably in the range of 5 to 25 in terms of an atomic ratio of silicon atom to titanium atom contained in the titanium compound (Si/Ti). The amount of the ester used is generally in the range of 0.05 to 10, preferably in the range of 0.1 to 6, and more preferably in the range of 0.2 to 3 in terms of a molar ratio of ester to titanium atom contained in the titanium compound (ester/Ti). The amount of the organomagnesium compound used is generally in the range of 0.1 to 10, preferably in the range of 0.2 to 5.0, and more preferably in the range of 0.5 to 2.0 in terms of an atomic ratio of the sum of titanium atom and silicon atom to magnesium atom (Ti+Si/Mg).
The solid product obtained by the reduction is subjected to solid-liquid separation and washed several times with an inert hydrocarbon solvent such as hexane, heptane or the like. The reduced solid product thus obtained contains trivalent titanium, magnesium, and a hydrocarbyloxy group and generally shows non-crystallinity or extremely weak crystallinity. The non-crystalline structure is especially preferable from the viewpoint of the catalytic performance.
The mixture of the ether and titanium tetrachloride and the organic acid halide are added successively in this sequence to the reduced solid product for treatment. Use of the organic acid halide decreases the amount of a cold xylene-soluble part, which is an amorphous polymer of less industrial value, and improves the polymerization activity and the bulk density of the polymer particles as well as the productivity.
The amount of the ether is generally 0.1 to 100 moles, preferably 0.5 to 50 moles, and more preferably 1 to 20 moles per 1 mole of a titanium atom contained in the reduced solid product. The amount of titanium tetrachloride is generally 1 to 1000 moles, preferably 3 to 500 moles, and more preferably 10 to 300 moles per 1 mole of the titanium atom contained in the reduced solid product. The amount of titanium tetrachloride per 1 mole of the ether is generally 1 to 100 moles, preferably 1.5 to 75 moles, and more preferably 2 to 50 moles. The amount of the organic acid halide is generally 0.1 to 50 moles, preferably 0.3 to 20 moles, and more preferably 0.5 to 10 moles per 1 mole of the titanium atom included in the reduced solid product. The amount of the organic acid halide per 1 mole of magnesium atoms included in the solid product is generally 0.01 to 1.0 moles and preferably 0.03 to 0.5 moles. The use of the excess amount of the organic acid halide sometimes causes degradation of particles.
Treatment of the reduced solid product with a mixture of the ether and titanium tetrachloride and the organic acid halide may be implemented by any known method of bringing these additives into contact with the solid product, for example, by a slurry method or by mechanical pulverization means such as a ball mill. The slurry method capable of bringing the additives into contact with the solid product in the presence of a diluent is, however, preferable for the production of the solid catalyst component having a narrow particle size distribution.
Examples of the diluent include: aliphatic hydrocarbons such as pentane, hexane, heptane, octane and the like; aromatic hydrocarbons such as benzene, toluene, xylene and the like; alicyclic hydrocarbons such as cyclohexane, cyclopentane and the like; halogenated hydrocarbons such as 1,2-dichloroethane, monochlorobenzene and the like. Among these examples, aromatic hydrocarbons and halogenated hydrocarbons are especially preferable.
The amount in volume of the diluent used is generally 0.1 ml to 1000 ml and preferably 1 ml to 100 ml per 1 g of the reduced solid product. The treatment temperature is generally in the range of xe2x88x9250 to 150xc2x0 C. and preferably in the range of 0 to 120xc2x0 C. The treatment time is generally 30 minutes or more, preferably 1 to 10 hours. After completion of the treatment, the treated solid product is allowed to stand for solid-liquid separation and washed several times with an inert hydrocarbon solvent thereby obtaining an organic acid halide-treated solid product.
The organic acid halide-treated solid product thus obtained is further treated with either a mixture of the ether and titanium tetrachloride or a mixture of the ether, titanium tetrachloride and the ester. The treatment is preferably performed in the form of slurry. Available solvents for preparation of slurry include: aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane and the like; aromatic hydrocarbons, such as toluene and xylene; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, decalin and the like; and halogenated hydrocarbons such as dichloroethane, trichloroethylene, monochlorobenzene, dichlorobenzene, trichlorobenzene and the like. Among these solvents, halogenated hydrocarbons and aromatic hydrocarbons are preferable.
The concentration of the slurry is generally in the range of 0.05 to 0.7(g-solid/ml-solvent) and preferably in the range of 0.1 to 0.5 (g-solid/ml-solvent). The reaction temperature is generally in the range of 30 to 150xc2x0 C., preferably in the range of 45 to 135xc2x0 C., and more preferably in the range of 60 to 120xc2x0 C. The reaction time is not specifically limited but generally 30 minutes to 6 hours.
The treatment of the organic acid halide-treated solid product with the ester, the ether and titanium tetrachloride may be implemented by adding the ester, the ether and titanium tetrachloride to the organic acid halide-treated solid product or, on the contrary, by adding the organic acid halide-treated solid product to a mixed solution of the ester, the ether and titanium tetrachloride. In the former process of adding the ester, the ether and titanium tetrachloride to the organic acid halide-treated solid product, it is preferable to add titanium tetrachloride after addition of the ester and ether or to add the ester, the ether and titanium tetrachloride simultaneously. It is especially preferable to add a mixture of the ester, the ether and titanium tetrachloride that has been prepared in advance to the organic acid halide-treated solid product.
Treatment of the organic acid halide-treated solid product with either a mixture of the ether and titanium tetrachloride or a mixture of the ester, the ether and titanium tetrachloride may be carried out repeatedly. It is preferable to repeat the treatment at least two times for the better catalytic activity and the stereoregularity.
The amount of the ether used is generally 0.1 to 100 moles, preferably 0.5 to 50 moles, and more preferably 1 to 20 moles per 1 mole of the titanium atom contained in the organic acid halide-treated solid product. The amount of titanium tetrachloride used is generally 1 to 1000 moles, preferably 3 to 500 moles, and more preferably 10 to 300 moles per 1 mole of the titanium atom contained in the organic acid halide-treated solid product. The amount of titanium tetrachloride per 1 mole of the ether is generally 1 to 100 moles, preferably 1.5 to 75 moles, and more preferably 2 to 50 moles.
In case that the ester coexists, the amount of the ester used is generally not more than 30 moles, preferably not more than 15 moles, and more preferably not more than 5 moles per 1 mole of the titanium atom contained in the organic acid halide-treated solid product.
The solid catalyst component thus obtained is subjected to solid-liquid separation and washed several times with an inert hydrocarbon solvent, such as hexane, heptane or the like prior to use for polymerization. In order to attain the better catalytic activity and stereoregularity, there is preferably adopted a method which comprises washing the solid catalyst component after the solid-liquid separation with a large amount of a halogenated hydrocarbon solvent such as monochlorobenzene or the like, or an aromatic hydrocarbon solvent such as toluene or the like, once or a plurality of times at the temperature of 50 to 120xc2x0 C., and subsequently washing several times the solid catalyst component with an aliphatic hydrocarbon solvent such as hexane or the like, followed by using the solid catalyst component for polymerization.
The solid catalyst component for xcex1-olefin polymerization (A) thus obtained is combined with the components (B) and (C) described above to give a solid catalyst for xcex1-olefin polymerization. The resulting catalyst has a high polymerization activity and gives a poly-xcex1-olefin of high stereoregularity. The solid catalyst component thus obtained has a narrow particle size distribution, which is not less than 6.0, preferably not less than 6.2, or more preferably not less than 6.4 in terms of the value of N in the Rosin-Rammler function of particle size distribution.
The obtained solid catalyst component has the catalytic activity of not less than 10,000 ((g-polymer produced/g-solid catalyst component)/hour).
The solid catalyst component for xcex1-olefin polymerization of the present invention is used in combination with appropriate co-catalyst components for polymerization of an xcex1-olefin. This gives a poly-xcex1-olefin having less fine powder and favorable particle properties. Typical examples of the co-catalyst components are organoaluminum compounds and electron-donor compounds, which are described in detail below.
(h) Organoaluminum Compound
The organoaluminum compound has at least one aluminum-carbon bond in the molecule. Typical examples of the organoaluminum compound are those represented by the general formulae given below:
R11xcex3AlY3xe2x88x92xcex3; and
R12R13Alxe2x80x94Oxe2x80x94AlR14R15
(wherein R11 through R15 represent hydrocarbon groups of 1 to 20 carbon atoms; Y represents a halogen, hydrogen, or an alkoxy group having 1 to 20 carbon atoms; 2xe2x89xa6yxe2x89xa63).
Concrete examples of the organoaluminum compound include: trialkylaluminums such as triethylaluminum, triisobutylaluminum, trihexylaluminum and the like; dialkylaluminum hydrides such as diethylaluminum hydride, diisobutylaluminum hydride and the like; dialkylaluminum halides such as diethylaluminum chloride and the like; mixtures of trialkylaluminums and dialkylaluminum halides such as a mixture of triethylaluminum and diethylaluminum chloride and the like; and alkylalumoxanes such as tetraethyldialumoxane, tetrabutyldialumoxane and the like.
Among these organoaluminum compounds, trialkylaluminums, mixtures of trialkylaluminums and dialkylaluminum halides and alkylalumoxanes are preferable. Especially preferable are triethylaluminum, triisobutylaluminum, a mixture of triethylaluminum and diethylaluminum chloride, and tetraethyldialumoxane.
The amount of the organoaluminum compound is generally in the wide range of 0.5 to 1000 moles, but is preferably in the range of 1 to 600 moles per 1 mole of the titanium atom contained in the solid catalyst component.
(i) Electron-donor Compound
Available examples of the electron-donor compound include: oxygen-containing electron donors such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic acids or inorganic acids, ethers, acid amides, acid anhydrides and the like; and nitrogen-containing electron donors such as ammonia, amines, nitrites, isocyanates and the like. Among these electron donors, esters of inorganic acids and ethers are preferably used.
The esters of inorganic acids are preferably silicon compounds represented by the general formula of R16nSi (OR17)4xe2x88x92n (wherein R16 represents a hydrocarbon group of 1 to 20 carbon atoms or hydrogen atom; R17 represents a hydrocarbon group of 1 to 20 carbon atoms; R16 and R17 may be the same or different in the same ether molecule; xe2x80x9cnxe2x80x9d represents a numeral satisfying 0xe2x89xa6n less than 4). Concrete examples include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, tert-butyltrimethoxysilane, isopropyltrimethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dipropyldimethoxysilane, propylmethyldimethoxysilane, diisopropyldimethoxysilane, dibutyldimethoxysilane, diisobutyldimethoxysilane, di-tert-butyldimethoxysilane, butylmethyldimethoxysilane, butylethyldimethoxysilane, tert-butylmethyldimethoxysilane, isobutylisopropyldimethoxysilane, tert-butylisopropyldimethoxysilane, hexylmethyldimethoxysilane, hexylethyldimethoxysilane, dodecylmethyldimethoxysilane, dicyloclopehtyldimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane, cyclopentylisopropyldimethoxysilane, cyclopentylisobutyldimethoxysilane, cyclopentyl-tert-butyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane, cyclophexylisopropyldimethoxysilane, cyclohexylisobutyldimethoxysilane, cyclohexyl-tert-butyldimethoxysilane, cyclohexylcyclopentyldimethoxysilane, cyclohexylphenyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, phenylisopropyldimethoxysilane, phenylisobutyldimethoxysilane, phenyl-tert-butyldimethoxysilane, phenylcyclopentyldimethoxysilane, vinylmethyldimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, butyltriethoxysilane, isobutyltriethoxysilane, tert-butyltriethoxysilane, isopropyltriethoxysilane, cyclohexyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, dipropyldiethoxysilane, propylmethyldiethoxysilane, diisopropyldiethoxysilane, dibutyldiethoxysilane, diisobutyldiethoxysilane, di-tert-butyldiethoxysilane, butylmethyldiethoxysilane, butylethyldiethoxysilane, tert-butylmethyldiethoxysilane, hexylmethyldiethoxysilane, hexylethyldiethoxysilane, dodecylmethyldiethoxysilane, dicyclopentyldiethoxysilane, dicyclohexyldiethoxysilane, cyclohexylmethyldiethoxysilane, cyclohexylethyldiethoxysilane, diphenyldiethoxysilane, phenylmethyldiethoxysilane, vinylmethyldiethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, phenyltri-tert-butoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, trimethylphenoxysilane, methyltriallyloxysilane and the like.
The ethers are preferably di-C1-20alkyl ethers or diethers represented by the general formula: 
(wherein R18 through R21 represent a linear or branched alkyl group of 1 to 20 carbon atoms or an aliphatic hydrocarbon, aryl or aralkyl group up to 20 carbon atoms; R18 or R19 may be hydrogen).
Concrete examples include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diamyl ether, diisoamyl ether, dineopentyl ether, dihexyl ether, dioctyl ether, methylbutyl ether, methylisoamyl ether, ethylisobutyl ether, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2-isopropyl-2-3,7-dimethyloctyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclohexylmethyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, and 2-heptyl-2-pentyl-1,3-dimethoxypropane.
Among these electron-donor compounds, organosilicon compounds represented by the general formula of R22R23Si(OR24)2 are especially preferable. In the general formula, R22 represents a hydrocarbon group of 3 to 20 carbon atoms having a secondary or tertiary carbon atom adjacent to Si. Concrete examples of R22 include: branched alkyl groups such as isopropyl, sec-butyl, tert-butyl, tert-amyl and the like; cycloalkyl groups such as cyclopentyl, cyclohexyl and the like; cycloalkenyl groups such as cyclopentenyl and the like; and aryl groups such as phenyl, tolyl and the like. R23 represents a hydrocarbon group of 1 to 20 carbon atoms, and concrete examples of R23 include: linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and the like; branched alkyl groups such as isopropyl, sec-butyl, tert-butyl, tert-amyl and the like; cycloalkyl groups such as cyclopentyl, cyclohexyl and the like; cycloalkenyl groups such as cyclopentenyl and the like; and aryl groups such as phenyl, tolyl and the like. R24 represents a hydrocarbon group having 1 to 20 carbon atoms and preferably a hydrocarbon group having 1 to 5 carbon atoms.
Concrete examples of the organosilicon compound used as the electron-donor compound include diisopropyldimethoxysilane, diisobutyldimethoxysilane, di-tert-butyldimethoxysilane, tert-butylmethyldimethoxysilane, tert-butylethyldimethoxysilane, tert-butyl-n-propyldimethoxysilane, tert-butyl-n-butyldimethoxysilane, tert-amylmethyldimethoxysilane, tert-amylethyldimethoxysilane, tert-amyl-n-propyldimethoxysilane, tert-amyl-n-butyldimethoxysilane, isobutylisopropyldimethoxysilane, tert-butylisopropyldimethoxysilane, dicyclopentyldimethoxysilane, cyclopentylisopropyldimethoxysilane, cyclopentylisobutyldimethoxysilane, cyclopentyl-tert-butyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane, cyclohexylisopropyldimethoxysilane, cyclohexylisobutyldimethoxysilane, cyclohexyl-tert-butyldimethoxysilane, cyclohexylcyclopentyldimethoxysilane, cyclohexylphenyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, phenylisopropyldimethoxysilane, phenylisobutyldimethoxysilane, phenyl-tert-butyldimethoxysilane, phenylcyclopentyldimethoxysilane, diisopropyldiethoxysilane, diisobutyldiethoxysilane, di-tert-butyldiethoxysilane, tert-butylmethyldiethoxysilane, tert-butylethyldiethoxysilane, tert-butyl-n-propyldiethoxysilane, tert-butyl-n-butyldiethoxysilane, tert-amylmethyldiethoxysilane, tert-amylethyldiethoxysilane, tert-amyl-n-propyldiethoxysilane, tert-amyl-n-butyldiethoxysilane, dicyclopentyldiethoxysilane, dicyclohexyldiethoxysilane, cyclohexylmethyldiethoxysilane, cyclohexylethyldiethoxysilane, diphenyldiethoxysilane, phenylmethyldiethoxysilane, and 2-norbornanmethyldiethoxysilane.
(j) Polymerization of Olefin
The xcex1-olefin applicable for the present invention is xcex1-olefins having 3 or more, preferably 3 to 10 carbon atoms. Concrete examples the olefin include: linear monoolefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene and the like; branched monoolefins such as 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene and the like; vinylcyclohexane, and the like. The xcex1-olefins may be used alone or in combination of 2 or more kinds for polymerization. Among these xcex1-olefins, homopolymerization of propylene or 1-butene and copolymerization of an olefin mixture including propylene or 1-butene as a main component are preferable. Especially preferable are homopolymerization of propylene and copolymerization of an olefin mixture including propylene as a main component. A mixture of ethylene and two or more olefins selected from the above xcex1-olefins may be applied for copolymerization in the present invention. A polyene compound such as conjugated diene and non-conjugated diene, may also be used in copolymerization. Hetero-block copolymerization, wherein polymerization is carried out in two or more stages, can be easily conducted.
The feeding of the respective catalyst components to a polymerizer is not specifically restricted, except that these catalyst components should be supplied under a water-free condition in an inert gas such as nitrogen or argon.
The solid catalyst component, the organoaluminum compound and the electron-donor compound may be supplied independently, or alternatively any two of them may be mixed together prior to the supply.
Polymerization of the olefin can be carried out in the presence of the above catalyst. Preliminary polymerization described below may be carried out prior to such polymerization (main polymerization).
The preliminary polymerization is carried out by feeding an olefin in a small amount in the presence of the solid catalyst component and the organoaluminum compound. The preliminary polymerization is preferably carried out in the state of slurry. Available solvents for preparation of slurry are inert hydrocarbons such as propane, butane, isobutane, pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene and the like. A part or the whole of the inert hydrocarbon solvent used for preparation of slurry may be replaced with a liquid olefin.
The amount of the organoaluminum compound used for preliminary polymerization is generally in the wide range of 0.5 to 700 moles, but preferably in the range of 0.8 to 500 moles and more preferably in the range of 1 to 200 moles per 1 mole of the titanium atom contained in the solid catalyst component.
The amount of the olefin to be preliminarily polymerized is generally 0.01 to 1000 g, preferably 0.05 to 500 g and more preferably 0.1 to 200 g per 1 g of the solid catalyst component.
The concentration of slurry for preliminary polymerization is preferably 1 to 500 g(solid catalyst component)/liter(solvent) and more preferably 3 to 300 g(solid catalyst component )/liter(solvent). The temperature of preliminary polymerization is preferably in the range of xe2x88x9220 to 100xc2x0 C. and more preferably in the range of 0 to 80xc2x0 C. The partial pressure of the olefin in the gas phase during preliminary polymerization is preferably 0.01 to 20 kg/cm2 and more preferably 0.1 to 10 kg/cm2; however, this does not apply to the olefin which is liquid at the temperature and pressure in the preliminary polymerization. The preliminary polymerization time is not specifically restricted but is generally in the range of 2 minutes to 15 hours.
The feeding of the solid catalyst component, the organoaluminum compound and the olefin in preliminary polymerization may be effected either by a method in which the olefin is fed after the solid catalyst component has been contacted with the organoaluminum compound or by a method in which the organoaluminum compound is fed after the solid catalyst component has been contacted with the olefin. The feeding of the olefin may be continuously fed while the pressure in the polymerizer is kept to a predetermined level. Alternatively the whole of the predetermined amount of the olefin may be fed initially. In order to adjust the molecular weight of the resulting polymer, a chain transfer agent such as hydrogen or the like, may be added.
The electron-donor compound may be, if necessary, added, while a small amount of the olefin is preliminarily polymerized in the presence of the solid catalyst component and the organoaluminum compound. A part or the whole of the electron-donor compound described above may be used as the electron-donor compound here. The amount of the electron-donor compound used is generally 0.01 to 400 moles, preferably 0.02 to 200 moles, and more preferably 0.03 to 100 moles per 1 mole of the titanium atom contained in the solid catalyst compound, and is generally 0.003 to 5 moles, preferably 0.005 to 3 moles, and more preferably 0.01 to 2 moles per 1 mole of the organoaluminum compound.
The method of feeding the electron-donor compound for preliminary polymerization is not specifically restricted. The electron-donor compound may be fed separately from the organoaluminum compound or may be previously contacted with the organoaluminum compound and then fed. The olefin used in preliminary polymerization may be the same as or different from the olefin to be used in the main polymerization.
After the preliminary polymerization or without the preliminary polymerization, main polymerization of the xcex1-olefin can be carried out in the presence of the catalyst for xcex1-olefin polymerization, which comprises the solid catalyst component, the organoaluminum compound and the electron-donor compound described above.
The amount of the organoaluminum compound used for main polymerization is generally in the wide range of 1 to 1000 moles, but preferably in the range of 5 to 600 moles per 1 mole of the titanium atom contained in the solid catalyst component.
The amount of the electron-donor compound used in main polymerization is generally 0.1 to 2000 moles, preferably 0.3 to 1000 moles, and more preferably 0.5 to 800 moles per 1 mole of the titanium atom contained in the solid catalyst component, and is generally 0.001 to 5 moles, preferably 0.005 to 3 moles, and more preferably 0.01 to 1 mole per 1 mole of the organoaluminum compound.
The main polymerization temperature is generally in the range of xe2x88x9230 to 300xc2x0 C. and preferably in the range of 20 to 180xc2x0 C. The polymerization pressure is not specifically restricted, but generally the ordinary pressure to 100 kg/cm2 or preferably the pressure of 2 to 50 kg/cm2 is adopted from the industrial and economical points of view. Both of the batch and flow systems are applicable for polymerization. Also available are slurry polymerization with an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, octane and the like, solution polymerization, bulk polymerization using as a medium an olefin which is liquid at the polymerization temperature, and gas phase polymerization.
In the main polymerization, a chain transfer agent such as hydrogen or the like, may be added in order to adjust the molecular weight of the polymer produced.